April had already pushed the button to close the doorway when Norman realized she’d made a terrible mistake: Dr. Winter’s hand was still lying in the hallway.

“Just leave it!” April pleaded.

Norman dropped to the ground and snatched Dr. Winter’s hand from outside the door just as it slammed shut.

Bullets smacked into the metal door. A string of obscenities hit the door seconds later.

“I’m not sure how long that will hold,” April said. “We’d better hurry.” She ran to the far wall, reached around her neck, and removed a thin chain with a key at the end of it, which she placed in the lock, turning clockwise until there was a faint click.

Fists banged on the door.

April smiled. “We might be in luck.”

Norman shoved Dr. Winter’s hand into his jacket pocket. “Severed hands, men with guns chasing us . . . I’d say luck is the one thing we don’t have.”

“No, you see, they must have only looked at the blueprints to the Jefferson portion of the Library of Congress.” She reached inside the vault and pulled out a large wooden box. It was highly polished and smooth as a wet stone. April unraveled a thin leather cord holding the box together and lifted the lid, revealing the marvelous Gutenberg, lying just as it had been for nearly five hundred years.

“If they had looked at the blueprints to the Adams or Madison Buildings, they would have realized that the underground tunnels that connect them to the Jefferson Building could also be reached from this vault,” April said, lifting the Gutenberg out of the velvet-lined box and setting it on one of the stainless-steel tables. She unbuttoned her blazer and took it off, wrapping it around the Gutenberg tightly and tying the sleeves around the top.

“Someone’s been hitting the gym,” Norman said, noticing April’s strong physique, now outlined by her fitted T-shirt.

April blushed. “No, it’s called being a mom,” she said. “Sometimes I call my son my personal trainer.” She looked at the Gutenberg package. Her blazer barely stretched around it. “I’m going to need your shirt too.”

Norman took off his jacket, begrudgingly removed his button-down, and handed it to her.

“Looks like you’ve been working out too,” April said, ripping his shirt in two and tying it at opposing angles around the Gutenberg.

“Please,” Norman said, putting his jacket back on over his sleeveless T-shirt, which bore a long stripe of sweat down its center.

The pounding grew louder. They were using something bigger— a fire extinguisher, Norman guessed—to hammer their way through. The extinguisher must be looking pretty battered about now.

April picked up the wrapped Gutenberg like an awkward duffel bag and threw it over her shoulder. She pushed back the table, revealing a panel in the floor.

“Even the secret passageways have secret passageways!” Norman said.